1. Field of Use
The present invention relates generally to the field of tumor mapping. More particularly, the present invention concerns tumor mapping methods, and apparatus, that use a multiple optical fiber probe. Specifically, a preferred embodiment of the present invention is directed to methods and apparatus that use a multiple fiber probe to obtain data for processing by a hybrid neural network so as to obtain an in-depth three dimensional mapping of an object, such as, for example, a tumor located within living tissue. The present invention thus relates to methods and apparatus of the type that can be termed in-depth three dimensional mapping.
2. Description of Related Art
As the technology of single photon detection has become more widely available, the technology of tumor diagnosis based on photonic detection has evolved. Heretofore, a surgeon or investigator has been able to place into a tumor region a fiber probe that is capable of both the delivery and reception of light. The distinct fluorescent emission detected at a single wavelength or an intensity spectral profile, from tumor and normal tissue has supported tumor diagnosis.
Recently, photosensitive tumor-seeking drugs with a strong absorption and large fluorescence quantum yield in the far visible or near infrared regions have become available. The characteristic spectral signature of these photosensitized drugs can improve early cancer diagnosis. Because near-infrared light can penetrate much deeper into tissue than visible and ultraviolet light, the use of such drugs makes possible tissue diagnosis at a significantly greater depth than was previously accessible.
Common endoscopic imaging has used coherent fiber bundles which is a straightforward method for direct in-vivo tissue diagnosis. The imaging system permits easy direct viewing, but such an imaging system is usable only at a macroscopic scale. Therefore, the tumor resolution with such an imaging system is relatively low. Further, imaging with such imaging systems is limited to surface sensing.
The present state of the art utilizes a single fiber probe for both laser excitation and fluorescence collection. Although this type of single fiber probe can be very sensitive for photon detection and thus indicate the presence absence of cancer, it cannot deliver such quantitative information as position, dimensions, distribution, and morphology of rumors. More importantly, because of the complicated optical properties of tissue optics, the background emission can easily mask the drug's fluorescence when a single fiber probe is being utilized.
What is therefore needed, is a highly sensitive system with a smart processing algorithm to eliminate these problems and permit accurate cancer diagnosis. No existing device can acquire quantitative tumor information through photonic spectral detection.